/* CSS: */
#alert {
    position: relative;
}

#alert:hover:after {
    background: hsla(0,0%,0%,.8);
    border-radius: 3px;
    color: #f6f6f6;
    content: 'Click to dismiss';
    font: bold 12px/30px sans-serif;
    height: 30px;
    left: 50%;
    margin-left: -60px;
    position: absolute;
    text-align: center;
    top: 50px;
    width: 120px;
}
#alert:hover:before {
    border-bottom: 10px solid hsla(0,0%,0%,.8);
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    content: '';
    height: 0;
    left: 50%;
    margin-left: -10px;
    position: absolute;
    top: 40px;
    width: 0;
}
#alert:target {
    display: none;
}
.alert {
    animation: alert 1s ease forwards;
    background-color: #c4453c;
    background-image: linear-gradient(135deg, transparent,
                      transparent 25%, hsla(0,0%,0%,.1) 25%,
                      hsla(0,0%,0%,.1) 50%, transparent 50%,
                      transparent 75%, hsla(0,0%,0%,.1) 75%,
                      hsla(0,0%,0%,.1));
    background-size: 20px 20px;
    box-shadow: 0 5px 0 hsla(0,0%,0%,.1);
    color: #f6f6f6;
    display: block;
    font: bold 16px/40px sans-serif;
    height: 40px;
    position: absolute;
    text-align: center;
    text-decoration: none;
    top: -45px;
    width: 100%;
}

@keyframes alert {
    0% { opacity: 0; }
    50% { opacity: 1; }
    100% { top: 0; }
}